Raised MCV- macrocytosis– may occur with or without anaemia. Physiological macrocytosis in the absence of anaemia occurs in neonates, especially those with Down syndrome, and during pregnancy.

Macrocytic anaemia- may be secondary to nutritional deficiencies in B12 and Folate leading to ineffective or abnormal erythropoiesis. This is easily diagnosed using simple blood tests. Where deficiency is excluded bone marrow examination may be required to identify rare causes such as myelodysplasia or Fanconi anaemia.

There are several drugs that may lead to macrocytosis, some of which are commonly used in the paediatric population. These include several chemotherapeutic agents, antibiotics and antiviral medications. It is also seen in congenital heart disease, hypothyroidism and Down Syndrome.

Additional investigations- guided by the history. It is important to check a reticulocyte count if a macrocytic anaemia is discovered. Reticulocytes are immature erythrocytes- which are large, and indicate increased erythropoiesis. Chronic reticulocytosis may falsely elevate the MCV. The absence of a raised reticulocyte count in the presence of severe anaemia suggests an inability of the bone marrow to produce red cells, eg due to inherited or acquired red cell aplasia.

Microcytosis– small red blood cells. Typically seen in iron deficiency anaemia; in the paediatric population at different ages the cause differs. In younger children and toddlers lack of supplementation may lead to deficiency. This is a particular issue in those that drink large volumes of cows milk as a substitute for iron containing foods. The main differential diagnosis is beta- or alpha-thalassaemia trait. Measurement of serum ferritin is the most useful test to identify iron deficiency- this will be low in iron deficiency and normal in beta- or alpha-thalassaemia trait.

In adolescence the pubertal growth spurt, and menorrhagia may be a causative factor. Further investigation will aid in determining the causes of microcytic anaemia (see below).

Part 2 of “Decoding the full blood count” with thanks to Dr Alexandra Briscoe, paediatric registrar at Whipps Cross University Hospital, and Professor Irene Roberts, professor of paediatric haematology at Oxford.

Haematocrit/packed cell volume

Haematocrit/ packed cell volume- the proportion of blood that is made up of cells (not plasma); it is measured as a percentage or fraction.

Low haematocrit is seen in anaemia, though it will not tell you the direct cause for the anaemia.

Raised haematocrit is seen in polycythaemia, in the newborn infant this is termed Neonatal Polycythaemia.

Defined as a venous haematocrit > 65%, occurring in 0.4-5% of healthy newborns. Symptoms are believed to be due to hyperviscosity. On examination children appear plethoric, and may have multi-systemic symptoms. These include- CNS features of irritability, cerebrovascular accidents and seizures. Apnoea and respiratory distress occur as a result of decreased pulmonary blood flow. In addition infants may demonstrate poor feeding, and may in rare cases develop necrotising enterocolitis (NEC.) Renal effects include renal vein thrombosis, oliguria, proteinuria and haematuria. Hypoglycaemia and thrombocytopenia (Vlug, 2013) are also seen commonly.

The development of polycythaemia occurs secondary to increased erythropoiesis as a consequence of chronic fetal hypoxia. IUGR and placental insufficiency- due to post-dates pregnancies, pre-eclampsia and maternal smoking, increase the incidence of polycythaemia. Infants of diabetic mothers, those with Beckwith –Weidemann, and congenital thyrotoxicosis are also at increased risk.

There has been much debate as to whether delayed cord clamping increases the incidence of polycythaemia. Current NICE guidelines recommend cord clamping between 1-5 minutes after delivery, provided there is no concern regarding the infant’s heart rate or need for resuscitation. In a Cochrane review of cord clamping practices and neonatal outcomes in 2013 McDonald et al found that delayed cord clamping was associated with increased risk of jaundice requiring phototherapy, however beneficial outcome in terms of iron stores- with a 50% reduction in iron deficiency at 3-6 months. They reported no difference in incidence of polycythaemia in 5 trials measuring this outcome.

Current management of symptomatic polycythaemia is a partial exchange transfusion.

Vitamin D deficiency in children with thanks to Dr Jini Haldar, paediatric registrar at Whipps Cross University Hospital.

Introduction

Vitamin D is an essential nutrient needed for healthy bones, and to control the amount of calcium in our blood. There is recent evidence that it may prevent many other diseases. There are many different recommendations for the prevention, detection and treatment of Vitamin D deficiency in the UK. The one outlined below is what we tend to do at Whipps Cross Hospital.

Prevention

The Department of Health and the Chief Medical Officers recommend a dose of 7-8.5 micrograms (approx. 300 units) for all children from six months to five years of age. This is the dose that the NHS ‘Healthy Start’ vitamin drops provide. The British Paediatric and Adolescent Bone Group’s recommendation is that exclusively breastfed infants receive Vitamin D supplements from soon after birth. Adverse effects of Vitamin D overdose are rare but care should be taken with multivitamin preparations as Vitamin A toxicity is a concern. Multivitamin preparations often contain a surprisingly low dose of Vitamin D.

Normal calcium (If <2.1 mmol/l in infants, refer as there is a risk of seizures)

If further assessment is required consider referral to specialist. **

Patient’s family is likely to have similar risk of Vitamin D deficiency – consider investigation ant treatment if necessary.

*Life style advice

1. Sunlight

Exposure of face, arms and legs for 5-10 mins (15-25 mins if dark pigmented skin) would provide good source of Vitamin D. In the UK April to September between 11am and 3pm will provide the best source of UVB. Application of sunscreen will reduce the Vitamin D synthesis by >95%. Advise to avoid sunscreen for the first 20-30 minutes of sunlight exposure. Persons wearing traditional black clothing can be advised to have sunlight exposure of face, arms and legs in the privacy of their garden.

2. Diet

Vitamin D can be obtained from dietary sources (salmon, mackerel, tuna, egg yolk), fortified foods (cow, soy or rice milk) and supplements. There are no plant sources that provide a significant amount of Vitamin D naturally.

As Vitamin D has a relatively long half-life levels will take approximately 6 months to reach a steady state after a loading dose or on maintenance therapy. Check serum calcium levels at 3 months and 6 months, and 25 – OHD repeat at 6 months. Review the need for maintenance treatment. NB: the Barts Health management protocol uses lower treatment doses for a minimum of 3 months and then there is no need for repeat blood tests in the majority of cases of children satisfying the criteria for management in primary care.

It is essential to check the child has a sufficient dietary calcium intake and that a maintenance vitamin D dose follows the treatment dose and is continued long term.

Follow-up:

Some recommend a clinical review a month after treatment starts, asking to see all vitamin and drug bottles. A blood test can be repeated then, if it is not clear that sufficient vitamin has been taken.

Neglect and emotional abuse is the safeguarding topic this month. ED advice on the management of minor head injuries, a report from BPSU in hypocalcaemic fits secondary to vitamin D deficiency, the new UK immunisation poster and a bit on crying babies. Hope you find it all helpful. Comments welcome below

Record the circumstances immediately before the onset of symptoms to help identify possible triggers

Consider taking blood samples for mast cell tryptase if reaction is thought to be immunologically mediated or idiopathic

First sample as soon after emergency treatment given

Second sample 1-2 hours (no more than 4 hours) from onset of symptoms

A further sample may be required at follow up with the allergy specialist to measure baseline mast cell tryptase

Children who have had emergency treatment should be admitted to hospital under the care of the paediatric team. The resus council suggests observing the child for a pragmatic (no evidence yet) 6 hours because of the risk of a biphasic reaction.

Offer the child/parents a referral to an allergy specialist (see www.bsaci.org for registered allergy clinics)

Offer the child/parents an adrenaline injector in the interim period whilst waiting for a specialist appointment

Information about the need for referral and the referral process to an allergy specialist

Information about patient support groups

Research Recommendations

Mast cell tryptase is not always elevated in children, particularly if food is thought to be the allergen or if respiratory compromise is the main clinical feature. It is recommended that further studies be carried out to identify other potential chemical inflammatory mediators.

There is limited evidence on biphasic reactions. Follow up studies are recommended.

There are no studies on length of observation period following emergency treatment for suspected anaphylaxis

There is limited data on the annual incidence or anaphylactic reactions and their associated outcomes.

The Guideline Development Group feel that referral to specialist services and/or the provision of adrenaline injectors are likely to benefit patients who have experienced a suspected anaphylaxis as a result of decreased anxiety and ongoing support. This benefit is yet to be quantified.

December 2011 has snippets of information on torticollis (backed up with lots more information on the website), unconscious children, alkaline phosphatase and a link to the Map of Medicine’s recent algorithm for cough in children. Also some pointers for your safeguarding training needs. Download it here.

Children who have hip pathology may present with a variety of non-specific symptoms. They may present with pain, refusal to bear weight, limp, or decreased movement of the lower extremity. If pain is present it is important to determine where it is coming from, as pelvis and low back pathology may refer pain to the hip region and hip pathology commonly presents with referred thigh or knee pain.[1]

The history should include

pain characteristics

trauma (recent/remote)

mechanical symptoms (catching, clicking, snapping, worse during or after activity)

Musculoskeletal exam including gait assessment: Look, Feel, Move approach to joint examination can be used. It should be noted that it is exceptionally rare to appreciate swelling of the hip on physical exam as it is a deep joint.

A CNS examination is also vital to exclude any neurological pathology.

Look for abdominal masses(Neoplasias in children can present with a simple limp)

Examine the genitalia(testicular torsion may present simply as a limp[2]) and perform an ENT examination

Look for rashes, bruises in unusual areas and remember the possibility of a non accidental injury.

Common differential diagnosis of limp by age:[2]

0-3 years

3-10years

10-15 years

Septic arthritis or OsteomyelitisDevelopmental dysplasia of hip(usually does not present with pain)Fracture or soft tissue injury (toddler fractures or non accidental injury)

Limp due to trauma: If a traumatic fracture is suspected perform an x ray of the affected site and involve the orthopaedic team as appropriate. Always consider the possibility of non accidental injury in a younger child presenting with fracture.

Atraumatic limp: The algorithm as below can be used for guidance. You may wish to give the parent information leaflet out as part of your “safety netting” as it reminds the family to seek further help if the limp is still present 1 or 2 weeks later.